Publishing their findings in the Journal of Neuroscience, researchers from the University of Calgary believe that probiotics work to alter the communication between the immune system and the brain, decreasing symptoms of fatigue, depression, and social withdrawal that are usually seen in chronic inflammatory diseases, like rheumatoid arthritis and inflammatory bowel disease. So far, researchers have examined a reduction in these symptoms within mice that had liver inflammation.

Furthermore, the processes of our gastrointestinal tract are carried out by microbiota. Its a mass of microorganisms that regulate digestion and our immune system health. Probiotics, consisting of many different cultures of live bacteria and yeasts, can help microbiota maintain digestive health when introduced into the gastrointestinal tract. Previous studies have also found that probiotics has positive effects on mood and cognition, but up until now, how probiotics interact with the brain has been relatively unknown. Researchers found the answer is linked to the immune system.

For the study of Chronic Inflammatory Diseases

Researchers examined how mice with liver inflammation responded to receiving probiotics or placebo. To measure how the mice responded to probiotics, researchers examined the length of time the mice engaged in social behaviors. As opposed to, the amount of time spent alone. In order to measure changes to brain function, researchers relied on previous research. This concluded that inflammatory disease often comes with increased production of the inflammatory signaling molecule. Its called tumor necrosis factor alpha (TNF-α). They then measured levels of TNF-α in the blood. As well as, the number of activated immune cells in the brain.

Overall, they found the mice who had received the probiotics spent longer amounts of time engaging in social behaviors. Unlike those who were fed a placebo. In fact, mice who were administered probiotics were also found to have lower levels of TNF-α. They found fewer immune cells in the brain being activated when compared to those in the control group. Interestingly enough, though, the probiotics did not appear to reduce the severity of liver inflammation, just its behavioral symptoms.

Findings from the Study

The researchers believe that their findings give evidence to the previous theory. The theory that probiotics help reduce behavioral symptoms by changing communication between the immune system and the brain. “In the setting of inflammatory disease, eating probiotics may be a novel way to improve the disease-associated symptoms that negatively impact the lives of patients,” study author Mark Swain said in a recent press release.

Other scientists within the field believe that this study has wider implications that extend to the possibility of treatment remedies. Keith Kelly, an immunophysiologist at the University of Illinois, believes the study has a lot of potential. “The global implication of data is that the gut microbiome can perhaps be manipulated to not only regulate immunity but also to regulate the neural circuitry that affects behavior,” he said.